Growth and body weight of European hares in southern Sweden

Body weight and growth of European hares Lepus europaeus Pallas in relation to environmental conditions, population density, age, sex, and reproduction were studied in three populations in southern Sweden on the basis of hares shot during October‐December. There were no significant differences in mean body weight of juveniles in the three areas. Differences in juvenile growth, as indicated by the correlation between eye lens weight (age indicator) and body weight, between areas and years were related to variations in nutrient conditions, in an island population it was probably also related to population density. Adult body weights did not differ between two mainland areas despite differences in food supply and population density, whereas island adult hares were, on average, significantly lighter than mainland hares. Also this difference was ascribed to nutrient conditions and/or population density. There were no significant differences in body weight between adult hares of different age classes. But reproductive females showed a significant positive correlation between number of litters produced annually and body weight. This relation indicates that reproduction is favoured by large body size and body weight, which also might explain the average higher mean body weight in females than in males. Juvenile hares showed no clear tendency in sex dimorphism of body weight.